You configure OSPF on a VRF instance the same way you configure the GlobalRouter, except that you must use VRF Router configuration mode and replace ipv6 with ipv6 ospf.
By default, OSPF Helper mode is enabled when OSPF is configured. You can disable helper mode by the following command and re-enable it again by using “no” or “default” commands.
enable
configure terminal
router ospf
ipv6 helper-mode-disable
no ipv6 helper-mode-disable
Or
default ipv6 helper-mode disable
Disabling Helper mode:
Switch:1>enable Switch:1#configure terminal Switch:1(config)#router ospf Switch:1(config-ospf)#ipv6 helper-mode-disable
Enabling Helper mode:
Switch:1>enable Switch:1#configure terminal Switch:1(config)#router ospf Switch:1(config-ospf)#no ipv6 helper-mode-disable